Suppose you are an interviewee and there are three ladies on the interview board. How would you greet them? Of course, in so far as I have learnt, you cannot say madams. What would you say? I have a faint idea of having read a grammar called Facts of English while I was at college and if my memory is clear there is a hint in that book that you can use "ladies" as the plural of "madam". I don't know whether my knowledge is a bit archaic;nevertheless, I would like native people to comment upon it.